A technique regarding a linear solenoid that has a plunger disposed on an inner side of a coil is disclosed in Patent Document 1 (JP 2011-119329 A). According to the linear solenoid of the Patent Document 1, a magnetic attractive core, a magnetic interruption part, and a magnetic delivery core are provided as a single member. The magnetic attractive core magnetically faces the plunger in an axial direction attracts the plunger. The magnetic delivery core has a tubular shape and surrounds the plunger. The magnetic delivery core delivers a magnetic flux to the plunger in a radial direction. The magnetic interruption part has a thin thickness and is a magnetically saturation part. The magnetic interruption part prevents the magnetic flux from directly flowing between the magnetic attractive core and the magnetic delivery core.
According to the linear solenoid of Patent Document 1, the magnetic attractive core and the magnetic delivery core are arranged on an inner side of a coil bobbin, and the plunger is arranged on an inner side of the magnetic attractive core and the magnetic delivery core. Accordingly, an outer diameter of the plunger is required to be small depending on a thickness of the magnetic attractive core and a thickness of the magnetic delivery core. Therefore, an area of a magnetic path of the plunger is restricted, and a magnetic attractive force of the plunger may be weakened.